Automatic voltage-regulator.



G. A. BURNHAM:

AUTOMATIC VOLTAGE REGULATOR.

APPLICATION FILED SEPT. 30, 1910.

Patented Apr. 4, 1911.

Gf@ 71g@ $1500 vroeg.

saaains Parana Eric.

GEORGE A. BURNHAM, or cLrE'roNnaLE,` MAssAcH'usErrs, AssIGlvo'E 'rosEAR-s B. ooNDI'r, JR., or Bos'roN, MASSACHUSETTS.

AUTOMATIC VOLTAGE-REGULATOR.

' which the following description, in connection with 'the accompanyingdrawings, is a specification, like letters on the drawings representinglike parts.

My invention is a voltage regulator, whose object is to provide suchahigh degree of efficiency that the introduction of the regu-V latorinto a working system will not be liable to interfere with thecontinuity of service.

Up to the present time it has frequently been the case that theintroduction of a voltage regulator would render the operation of thesystem more uncertain than it was without the regulator, because of thepossibility, and in fact liability, of the regulators refusing `to workat a critical moment on account of the freezing of the contacts.Accordingly my invention aims to provide a regulator which practicallyeliminates the tendency to impair or dest-roy the continuity of service,and I accomplish this by introducing means which is responsive tochanges in voltage in the main line to cut in resistance into the fieldcircuit in such a manner that it is practically impossible for themake-and-break device to stick, bug, or freeze, irrespective of whetherthe interruptions are rapid or slow. I provide a continuously moving andpreferably rotating contact or pair of contacts, cooperating with areciprocating contact or pair of contacts, having relative frictionalengagement, preferably of a positive rubbing nature when thereciprocating contact engages the rotating contact. The result is thatmy voltageregulator has a high degree of efhciency as to certainty andcontinuity of action and practical immunity from breakdowns.

In the drawings, Figure V1 is a view largely diagrammatic and partlysectional of a preferred embodiment of the invention; and Fig. 2 is asimilar view of a modified construction.

It will be understood that my mechanism is adapted to -a variety of usesand wiring arrangements, and that I have herein' shown the same inconnection with a generator and its circuit, -merely as a means ofmaking the invention clearly intelligible. As shown, the

` Specification of Letters Patent.

Application `filed September 30, 191.0.

Patented Apr.. at, 1913.11. serial No. 584,725.

generator to b'e regulated is indicated at 1 connected in usual mannerto feed wires 2, 3, supplying current to a load 4, said generator havinga usual field 5. Across the circuit 2, 3, is connected a voltmeter 7whose needle 8 connects with any suitable source of supply, as a battery9, by means of a wire 10, the wire 11 from the opposite end of saidsource of supply branching at l2 to the solenoids 13, 14, the oppositeends of whose windings connect by wires 15, 16 to the contacts 17, 18 ofthe voltmeter, all in usual manner. Pivoted to rock at 19 is a conductorbar or lever 20 provided with a brush 21 arranged to coperatealternately with a member or mechanism, comprising rotary contacts 22,23 fast on an insulated driving shaft 24, driven by any suitable poweras by a motor 6. Brushes 25, 26 connect from the rotary contacts 22, 23respectively with resistances 27 28 connected by a wire 29 in yserieswith the field 5 of the generator 1,

said circuit being completed from the opposite side of the generator bya wire 30 to the contact lever 20. A condenser 31 is shown as connectedacross from the wire 29 to the wire 30. A springs 32 tends to hold thecontact arm 20 always in normal 'posi'- tion against the rot-ary contact22. In Fig. 2, instead of the two wheel-like contacts 22, 23, I providea hollow or box-like rotary member33 on a motor-driven shaft 34 the sameas before, and containing the two resistances 27, 28 connected to aperipheral ring 35 engaged by a brush 36 of the wire 29. At theiropposite ends said resistances connect respectively to face rings 37, 38engaged by contacts 39. 40 on a rock bar or transverse head 4l of thecontact lever 20, the remainder of the mechanism being the same asalready described in connection with Fig. 1.

IVhile the construction and operation thus far described are preferable,the point of paramount importance is that the contact shall haverelative rubbing movement and action at the moment of break, andpreferably at the moment of both make and break. This renders itpractically impossible for any bugging or freezing to take place. At themoment the vibrating contact tends to leave the rotating disk an arc isformed which tends to melt the separating surfaces. If one of thesurfaces is stationary so that the separating movement is straightout,awayfrom they other in a direction substantially at right angles totheir mutually engaging surfaces, and the only ower with which to pullthe metal apart 1s the very slight power of the relay or electromagnetcoupled with the very slight movement of the vibrating member, therewillbe a strong liability of their sticking or fusing together, whereasby combining with this straight-out movement a simultaneous lateral orshearing movement substantially in the direction of the plane of theirengaging surfaces, .e., by combining with the straight-out movenient ofthe vibrating member the rotary movement of the rotary member, thistendency of the parts to fuse together is prevented. The same benefit,but in less degree, arises from having the combined outward and shearingmovement, z'. e., the rubbing action, take place on the contact makingmovement when the circuit is closed. Furthermore, by maintaining therubbing action while the contacts aretogether, their engaging surfacesare kept in the best condition.

In operation, the continuously driven rotary contacts Q2, Q3 (Fig: l),37, 8S (Fig. 2 operate to bring continuously a new makeand-break`surface in operative position to be engaged with the reciprocatingcontact. or contacts Q1, Fig. l, or 39, 40, Fig. 2, so that theapparatus continues to operate uniformly, continuously and withoutliability7 to stick or freeze. lnasmuch as the motor driven contacts arecontinuously moving and are intermittingly engaged by the reciprocatingcontacts, it necessarily results that there is a continually recurrentrubbing action between the reciprocating contacts and the rotarycontacts. This rubbing action is preferably supplemented by having thereciprocating contacts capable of yielding or turning on their axes, theprincipal object, however, being to provide the foregoing rubbing actionand continuously changing contacting surface, irrespective of the speedof the make and break action, so that all tendency to bug or freeze iseliminated. lVhenever there is a variation in potential in the maincircuit 2, 3, there results a corresponding movement in the voltmeter 7,causing the needle 8 to move to the right or left, thereby energizingone or the other of the solenoids 13, 14 so as positively to move thecontact lever 20 in a corresponding direction, bringing its contact orcontacts into the before mentioned sliding or rubbing engagement withthe continuously rotating contacts of the make-and-break device. Thiscuts in one of the resistances and cuts out the other, correspondinglychanging the value of the field flux. The provision of the tworesistances 27, 28 of different value in connection with the meansdescribed for cutting out one and cutting in the other, or vice versa,results in a further advantage. The value of said resistances is eithertoo higher too low to give normal voltage atthe generator. By

introducing the resistance 27, as distin guished from short-circuitingthe resistance 28, I am able materially to reduce the tendency ofsparking at the break between the reciprocating contact and one or theother of the rotary contacts, as the case may be.

.Having describedmy invention, what l claim as new and desire to secureby Letters Patent is,

1.ln a voltage regulator, two contact members, means for imparting arelative make-and-break movement thereto, and means for moving one ofsaid members at a relatively high speed whereby a relative transverseshearing movement is imparted atgthe instant of separation.

Q. ln a voltage regulator, two contact members. means for impartingrelative make-and-break movement thereto, and

.means for moving one of said members at a relatively high speed at theinstant of making and breaking the contact, .-.whereby a transversemovement'is imparted as the contact is made and broken.

El. ln a voltage regulator. two contact members `mounted formake-and-break movement. means for imparting relative intermittentmovement thereto to make and break the circuit, and means for moving oneof said members at the instant of separation in a direction transverseof said former movement whereby a transverse shearing movement isimparted at the instant of separation, in vaddition to said intermittentmake-and-break movement.

et. In a voltage regulator, two contact members mounted formake-and-break movement, means for imparting relative intermittentmovement thereto to make and break the circuit, and means for drivingone of said members in 4a. direction angular relative to said formermovement as the contact is made and broken, whereby a transverseshearing movement is imparted as the contaets come together andseparate.

5. In a voltage regulator. two contact members mounted formake-and-break movement, means for imparting intermittent movementthereto to make and break the circuit, and means for driving one of saidmembers at a constant relatively high speed whereby a transverseshearing movement is imparted at the instant of contact separation.

6. ln a voltage `regulator, two contact mcmbers,' means for impartingrelative make-and-break movement thereto, and means for .imparting aseparate relatively high speed movement to one of said members in adirection at right angles to said makeand-break movement, whereby atransverse shearing action is effected at the instant of contactseparation.

7. In an apparatus of the kind described a generator for supplying amain circuit, its field and field circuit, and automatic makeand-breakmeans for varyingthe value of the field fiuX, including a resistance andtwo intermittingly engaging contact members adapted to make anintermittent rubbing" 'contact members adapted to make .an '1ntermittentrubbing contact, one contact member being continuously movable.

9. An apparatus of the kind described,"

comprising a generator, its field and field circuit, a main circuitcontaining translating devices, two intermittingly engaging contactmembers adapted to make a continuously rubbing contact and havingrelative make-and-break. movement, means to move one of said contactmembers to bring a new contact surface into contact-breaking positionfor each circuit opening operation, means responsive to variations ofvoltage iii said main circuit for interinittingly operating saidcontacts to close the circuit at varying intervals, and means responsiveto the make-and-break action of" said two contacts, including saidfield, for bringing about a desired voltage in said main circuit.

10. An apparatus of the kind described, including a generator, its fieldand\field circuit, a main circuit, at least two coperating contactmembers adapted to make an intermittent rubbingcontact at eachmake-andbreak act-ion, means for moving one of said contact members tobring a new surface into position to coperate with the other contact'member, mechanism for moving said other contact member, includingelectromagnetic means. responsive to variations of voltage in said maincircuit, said two contacts being adapted to have their new surfaceengagement for each circuitl opening.

operation independent of the voltage influence, and means responsive tothe make-andbreak action of said two contacts, including said field, forbringing about a desired voltage in the main circuit.

11. An apparatus of the kind described,

i including a generator, its field and field circuit, a maincircuit, atleast two cooperating f contact members adapted to make a rubbingcontact, mechanism for moving one of Zsaid 'contact members into contactwith the other, including electro-magnetic lmeans responsive tovariations of voltage in said main circuit, means independent of saidmechanism for moving said other contact member for bringing a newcontacting surface into position for each engagement of saidfirstmentioned contact member and providing a relative rubbing movementand action at the movement of break, and means responsive to themake-and-break action of said two members, including said field, formaintaining a desired voltage in the main circuit.

12. An apparatus of the kind described, including a generator, its fieldand field circuit, a main circuit, two resistances different in value,operatively and independently related tol the field, each to have avariable effect thereon, one of said resistances containing a greateramount of resistance then required for normal voltage in said maincircuit, andthe other of said resistances containing a less amount ofresistance then required for normal voltage in said main circuit, andautomatic means responsive to va.- riations of voltage in the maincircuit for varying t-he value of the 4field current by said resistancesalternately, including makeand-break means adapted to make a rubbingcontact at each operation for continuously cutting said respective tworesistances alternately in and alternately out.

13. An apparatus of the kind described, comprising a generato-r auditscircuit and field, combined with two resistances different in valueoperatively related to the field, and automatic means for varying thevalue of the field flux by said resistances alternately, said meanscutting in one resistance and cutting out the other and vice versacontinuously, said automatic means including two coperating contactmechanisms operable in said fieldcircuit in response to varia.- tions ofvoltage in said main circuit, one mechanism movable toward and from theother and adapted to make a rubbing contact, and said other beingmovable continuously to bring a new contact surface into makeand-breakposition for each make-and-break operation.

14. An' apparatus of the kind described, including a field and itscircuit, two resistances diHerent value operatively related to thefield, and continuously opera-ting means for continuously varying thevalue of the field flux by said resistances alternately in response to.variations of voltage in said circuit, said continuously operating meansincluding' make-and-break members adapted to make a rubbing contact.

15. An automatic voltage regulator, comprising a generator, its field,and field circuit, a main circuit operated by said generator, acontinuously movable contact member, a coperating variable vibratingcontact member, electromagnetic means to operate said variable vibrating`contact member in response to variations in voltage in said maincircuit, and means influenced by the ma-ke-and-break action of said twoContact members, including said field, for maintaining thedesiredvoltage in'said main circuit.

16. An automatic voltage regulator, oomprising a rotary Contactmechanism having two rotary Contact portions insulated from each other,a separate resistance for each portion, and a movable Contact memberalternately movable between said portions from one to the other torender said resistances alternately elective.

1T. An auto-matic voltage regulator, comprising a pivoted Contactmember, electromagnetic means for rocking said member on lits pivot, andcoperating Contact mechanism having separated Contact portions tocooperate with separate Contact surfaces of said pivoted contact memberas the latter rocks on its pivot, a. high resistance in series with oneof said Contact portions and a low resistance in series with the otherof said Contact portions.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing Witnesses.

GEORGE A. BURNHAM.

YVitnesses:

GEO. H. MAXWELL, WM. J'. PIKE.

